Lab 11:Early Invertebrates and phylogeny

fbdfdf

Spicules

; Needle-like support structures in sponges

Spongocoel

; Central cavity inside a sponge

Osculum

; Large opening where water exits a sponge

Polyp(cnidarian)

; Sessile, tube-shaped body form of cnidarians

class anthozoa  usually corals

Medusa (cnidarian)

Free-swimming, bell-shaped body form of cnidarians

class scyphozoa usually jellyfish

class cubozoa usually box jellyfish

Mouth (Planarian) ;

Opening on ventral side used for feeding

Flame Cells (Planarian)

; Excretory cells that remove waste

Eye Spots (Planarian)

; Light-detecting organs on the head

Scolex (Tapeworm)

; Head region with hooks/suckers for attachment

Sypha

Porifera; simple tube sponge

Leucosolenia

Porifera; small branching sponge

Obelia

Cnidaria (Hydrozoa); colonial polyp with medusae stage

Hydra (cnidarian)

Cnidaria (Hydrozoa); solitary freshwater polyp

Planarian

Platyhelminthes (Turbellaria); free-living flatworm

Tapeworm

Platyhelminthes (Cestoda); parasitic flatworm with scolex and proglottids

porifera (Parazoa)

Sponges; asymmetrical, no true tissues, filter feeders with spicules and spongocoels

reproduces asexually (budding) and sexually(releasing sperm)

Parazoa (phylum)

lack true tissue

sponges

asymmetry 

includes phylum’s placozoa and porifera 

only one species trichoplax adhaerens

Cindarians (phylum)

usually have radial symmetry and diploblastic  (radiata)

Can either be polyp or medusa 

sexual reproduction and asexual 

shares one opening forr everything 

Ctenophora (separate from cindiarains phylum)

includes comb jellies

are diploblastic and have radial symmetry  

do not have cnidocytes

have a complete gut

Flatworms Lophotrochazoans

bilateral symmetry and triploblastic (or three germ layers)

true body

include brachiopods molluscs annelids flatworms rotifers and ectoprocts

to be one needs to have a lophophore ( a mouth with cilia »)

or a trochophore which is like 2 facing each other

Phylum Platyhelminthes (lophotrochozoans)

are flat worms

only one opening basal taxon

lack lophophore and trochophore but similar DNA

hermaphroditic (so both male and female parts)

flame cells

Rotifers (lophotrochozoans)

freshwater organism

has separate anus and mouth and pseudocoelom 

reproduce by parthenogenesis 

Ectoprocts (lophotrochozoans)

also known as bryzoans 

animals that resemble plants

some are reef builders

Nemertea (lophotrochozoans)

Also known as ribbon worms 

bottom dwellers

Brachiopods(lophotrochozoans)

look like shelled molluscs

attach to seafloor by a stalk

Annelids(lophotrochozoans)

are coelomates with bodies with rings

segmented worms repeated body segments

most advanced worm

complete digestive system (picture earthworm)

Oligiochaeta(earthworm) (lophotrochozoans)

contains earthworms and leaches

earthworms are distinguished  by the thick band

they eat soil extracting nutrients 

subclass Hirudinea (leaches) (lophotrochozoans)

most live in freshwater they are parasites that suck blood

they have a chemical called hirudin to prevent blood from coagulating

polychaeta (marineworms) (lophotrochozoans)

paddle like structures called parapodia on each body segment

each  body has chitin which are bristles 

Ecdysozoans )

covered by a tough coat called a cuticle mad of chitin  

the cuticle is shed or molted through a process called ecdysis 

2 largest phyla are nematodes and arthropods 

 

nematoda (Ecdysozoans )

usually roundworms

have alimentary canal and lack circulatory system 

Targigrada (Ecdysozoans )

live in water 

called water bears because of claws and legs

can enter a state called crypto biosis 

Arthropods (Ecdysozoans )

meaning jointed legs/ feet

domiantes the animal kingdom

exoskeleton made of chitin

includes arachnids hexapods crustations

Hexapoda Arthropods (Ecdysozoans )

Includes 6 legs on insects like bees and flies insect wings are an extention of the cuticle

Myriapoda arthropods (Ecdysozoans )

includes chilopods and diplopda which are centipedes and millipedes

have antennaes and three appendages

 Crustacea Arthropods (Ecdysozoans )

include mostly aquatic things like decapods

krill shrimp lobster crabs and crayfish

 Chelicerata Arthropods (Ecdysozoans )

spiders horseshoe crabs ticks mites and scorpions 

have anterior cephalothorax and posterior abdomen 

incomplete metamorphosis vs complete